Construction machine

Abstract

In a construction machine having an engine room and capable of efficiently collecting air flowing in the engine room, a heat exchanger provided at a first side of the engine, and a fan provided at the first side and rotating to generate around the engine a flow of cooling air, further includes an exhaust duct extending in a fan axial direction parallel with a rotation axis of the fan along the engine. The exhaust duct guides the flow of the air to collect the air flowing downstream of the fan in the fan axial direction, in a region extending in the fan axial direction, and discharges the air to an outside of the engine room.

The invention claimed is: 
     
       1. A construction machine comprising:
 an engine room; 
 an engine housed in the engine room; 
 a heat exchanger provided at a first side as one side in a longitudinal direction of the engine; 
 an axial-flow fan provided at the first side of the engine and adapted to be rotated to generate, around the engine, a flow of cooling air which enters the engine room from an outside of the engine room and passes through the heat exchanger, the flow containing respective direction components in a rotational direction, a centrifugal direction, and an axial direction, of the fan; and 
 an exhaust duct having an air inlet opening and an air outlet opening and provided in the engine room so as to extend in a fan axial direction parallel with a rotation axis of the fan along the engine, the exhaust duct adapted to guide the flow of the air so as to collect the air, which flows at a downstream side of the fan in the fan axial direction, in a region extending in the fan axial direction and so as to discharge the air to an outside of the engine room, 
 wherein the exhaust duct has the air inlet opening at an upper part thereof, the air inlet opening located at a position higher than a bottom of the engine, and has the air outlet opening at a lower part thereof at a position lower than the air inlet opening, the exhaust duct being disposed in front of or behind a lower part of the engine so as to suction the air flowing around the engine from above and discharge the air from below by matching a swirling direction of the flow of the air generated by the fan. 
 
     
     
       2. The construction machine according to  claim 1 , wherein the exhaust duct is provided over substantially a whole region of the engine in the fan axial direction, and the air inlet opening and the air outlet opening are formed over substantially a whole length of the exhaust duct in the fan axial direction. 
     
     
       3. The construction machine according to  claim 1 , wherein the construction machine includes: a frame including a part which configures a floor of the engine room; a partition member provided to stand up in a posture of extension substantially in parallel with a longitudinal direction of the engine on the frame to define the engine room at a rear part of the frame; and a duct body in a frame shape surrounding a space opened frontward, the duct body being attached to a rear-side surface of the partition member to form the exhaust duct in cooperation with the partition member. 
     
     
       4. The construction machine according to  claim 1 , further comprising an air guide member for collecting air having passed in the fan axial direction through a region in which the exhaust duct collects the air, at a downstream side of the region, and for guiding the air to the exhaust duct. 
     
     
       5. The construction machine according to  claim 1 , wherein the exhaust duct has a shape being bent between the air inlet opening and the air outlet opening. 
     
     
       6. The construction machine according to  claim 5 , wherein the exhaust duct is bent along a direction in which air swirls around the fan. 
     
     
       7. A construction machine comprising:
 an engine room; 
 an engine housed in the engine room; 
 a heat exchanger provided at a first side as one side in a longitudinal direction of the engine; 
 an axial flow fan provided at the first side of the engine and adapted to be rotated to generate, around the engine, a flow of cooling air which enters the engine room from an outside of the engine room and passes through the heat exchanger, the flow containing respective direction components in a rotational direction, a centrifugal direction, and an axial direction, of the fan; 
 an exhaust duct having an air inlet opening and an air outlet opening and provided in the engine room so as to extend in a fan axial direction parallel with a rotation axis of the fan along the engine, the exhaust duct adapted to guide the flow of the air so as to collect the air, which flows at a downstream side of the fan in the fan axial direction, in a region extending in the fan axial direction and so as to discharge the air to an outside of the engine room; 
 an air guide member for collecting air having passed in the fan axial direction through a region in which the exhaust duct collects the air, at a downstream side of the region, and for guiding the air to the exhaust duct, 
 a hydraulic pump provided at a second side of the engine opposite to the first side; and 
 a pump cover for covering the hydraulic pump to shield at least a part of the hydraulic pump from the engine, the pump cover having an air inlet for taking in air flowing around the engine and an air outlet for discharging the taken-in air into the exhaust duct to function as the air guide member. 
 
     
     
       8. The construction machine according to  claim 7 , wherein the pump cover has a shape having an opening at a lower end and covering the hydraulic pump at an upper side thereof to discharge air flowing in through the opening to the exhaust duct.